Gravity plate settlers are known for use in water treatment facilities for separating solid impurities from an influent flow of fluid. Typically, a plurality of parallel plates are connected in series in a settling tank. The influent flow of fluid is distributed across the width of the plates and then flows upwardly under laminar flow conditions. The solid impurities settle on the plates while the fluid that has been depleted of the solid impurities exits from the plates as effluent at the top.
One example of a gravity plate settler is U.S. Pat. No. 5,049,278 to Galper. This patent discloses a modular plate settler comprising inlet ports for receiving an influent flow of liquid, a settling tank for settling and collecting solids separated from the influent flow of liquid, outlet weirs for discharging an effluent flow of clarified liquid, a parallelogram shaped enclosure provided with a full bottom opening for receiving the influent flow of liquid from the settling tank, and a plurality of inclined parallel gravity settling plates within the enclosure. The influent flow of liquid passes over the settling plates toward a full top opening such that the solids settle on the plates and slide downwardly under gravitational force into the tank. As a result, the flow of liquid is clarified of solids and flows through the top opening and effluent trough toward the outlet weirs.
It is desired to provide a new and improved method and apparatus for separating solid impurities from a fluid containing solid impurities using a gravity plate settler in which the influent is prevented from mixing with or stirring up the solid impurities already separated from the influent stream. This prevention of mixing or stirring may have the effect of improving the overall efficiency of the gravity plate settler.